(1) Field of the Invention
The present invention related to the synthesis and biological activity of indoloazepines and acid amine salts thereof which are structurally related to naturally-occurring hymenialdisine. The chemically-synthesized indoloazepines inhibit production of IL-2 and TNF-α. Exposure of the chemically-synthesized indoloazepine to mammalian Jurkat leukemia T-cells and THP-1 cells results in a dose response inhibition of IL-2 production and TNF-α production, respectively. The indoloazepines are useful for treating inflammatory diseases, particularly diseases associated with NF-κB or GSK-3β activation and NF-κB activated gene expression.
(2) Description of Related Art
Elevated levels of cytokines, such as interleukin-1 (IL-1), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) have been linked to many inflammatory disorders including Crohn's disease and psoriasis, and play an essential role in the pathogenesis of rheumatoid arthritis and osteoarthritis (Gerard et al., Nat. Immunol. 2: 108-115 (2001); Inoue et al., Inflamm. Res. 50: 65-72 (2001); Polisson, Curr. Rheumatol. Rep. 3: 489-495 (2001); Miossec, Cell Mol. Biol. (Noisy-le-grand) 47: 675-678 (2001); Roshak et al., J. Pharmacol. Exp. Ther. 283: 955-961 (1997); Harris, N. Engl. J. Med. 322: 1277-1289 (1990)).
Using anti-inflammatory drugs to inhibit cytokines, in particular TNF-α, has been successful in several clinical trials for treating rheumatoid arthritis (Moreland, J. Rheumatol. 26 Suppl. 57: 7-15 1999); Moreland, et al., N. Engl. J. Med. 337: 141-147 (1997)). However, there is variability in responses to these anti-inflammatory drugs because of the complex network of alternative cytokine mediated pathways (Miossec, Cell Mol. Biol. (Noisy-le-grand) 47: 675-678 (2001); Handel et al., Clin. Exp. Pharmacol. Physiol. 27: 139-144 (2000)). Using drugs which inhibit transcription factors that control the expression of several pro-inflammatory mediators, such as the nuclear transcription factor NF-κB, may overcome response variability and may provide an alternative strategy for treating a wide variety of inflammatory disorders (Makarov, Arthritis Res. 3: 200-206 (2001); Tak, J. Clin. Invest. 107: 7-11 (2001); Roshak et al., Curr. Opin. Pharmacol. 2: 316-321 (2002); Yamamoto and Gaynor, J. Clin. Invest. 107: 135-142 (2001); Feldmann et al., Ann. Rheum. Dis. 61 Suppl. 2: ii13-18 (2002); Barnes and Karin, N. Engl. J. Med. 336: 1066-1071 (1997); Lee and Burckart, J. Clin. Pharmacol. 38: 981-993 (1998); Baldwin, Ann. Rev. Immunol. 14: 649-683 (1996); Miagkov et al., Proc. Natl. Acad. Sci. USA 95: 13859-13864 (1998); Guttridge et al., Mol. Cell Biol. 19: 5785-5799 (1999); Baeuerle and Henkel, Ann. Rev. Immunol. 12: 141-179 (1994)).
Because of its critical role in the regulation of inflammatory responses, NF-κB has become an increasingly significant therapeutic target for controlling diseases such as asthma, rheumatoid arthritis, multiple sclerosis, and Alzheimer's disease (Tak, J. Clin. Invest. 107: 7-11 (2001); Yamamoto and Gaynor, J. Clin. Invest. 107: 135-142 (2001); Barnes and Karin, N. Engl. J. Med. 336: 1066-1071 (1997); Boland, Biochem. Soc. Trans. 29: 674-678 (2001); Hart et al., Am. J. Respir. Crit. Care Med. 158: 1585-1592 (1998); Yamamoto and Gaynor, Curr. Mol. Med. 1: 287-296 (2001)).
Hymenialdisine is a bromopyrrole alkaloid which was originally isolated from the marine sponges Axinella verrucosa and Acantella aurantiaca. Its structure was established on the basis of X-ray crystallography (Cimino et al., Tet. Lett. 23: 767-768 (1982)). The structure of hymenialdisine is shown in FIG. 1A. Hymenialdisine has been found to inhibit various proinflammatory cytokines, such as IL-1, IL-6, IL-8, and nitric oxide in a variety of cell lines (Inoue et al., Inflamm. Res. 50: 65-72 (2001); Roshak et al., J. Pharmacol. Exp. Ther. 283: 955-961 (1997); Breton and Chabot-Fletcher, J. Pharmacol. Exp. Ther. 282: 459-466 (1997); Badger et al., J. Pharmacol. Exp. Ther. 290: 587-593 (1999)). Investigation of the promising anti-inflammatory properties of hymenialdisine revealed that it inhibits cytokine production by inhibiting the NF-κB signaling pathway (Roshak et al., J. Pharmacol. Exp. Ther. 283: 955-961 (1997); Breton and Chabot-Fletcher, J. Pharmacol. Exp. Ther. 282: 459-466 (1997); Badger et al., J. Pharmacol. Exp. Ther. 290: 587-593 (1999); Badger et al., Osteoarthritis Cartilage 8: 434-443 (2000)). Gel shift analysis showed that this inhibition was that hymenialdisine selectively reduced NF-κB nuclear binding and not the binding of other transcription factors such as C/EBP, AP-1, or SP1 (Roshak et al., J. Pharmacol. Exp. Ther. 283: 955-961 (1997)).
Recently, Meijer et al. reported that the potent NF-κB inhibitor hymenialdisine acts as a competitive nanomolar inhibitor of the cyclin-dependent kinases GSK-3β and CK1 (Meijer et al., Chem. Biol. 7: 51-63 (2000)). Crystallographic data showed that hymenialdisine binds to the ATP binding pocket of the GSK-3β and CK1 kinases (Meijer et al., Chem. Biol. 7: 51-63 (2000)). Considering the potential relationship between NF-κB activation and GSK-3, that might suggest a potential pathway for this kinase inhibitor (Meijer et al., Chem. Biol. 7: 51-63 (2000); Ali et al., Chem. Rev. 101: 2527-2540 (2001); Schwabe and Brenner, Am. J. Physiol. Gastrointest. Liver Physiol. 283: G204-211 (2002)). In addition, Ireland et al. identified hymenialdisine as a very potent MEK-1 inhibitor with low nanomolar IC50 values. This suggests that hymenialdisine may be useful as an antiproliferative agent (Tasdemir et al., J. Med. Chem. 45: 529-532 (2002)).
Hymenialdisine and various derivatives thereof such as debromohymenialdisine have been disclosed in the following patents and published patent applications.
U.S. Pat. No. 5,565,448 to Nambi et al. discloses medicants which contain hymenialdisine or debromohymenialdisine and which are used to inhibit protein kinase C and U.S. Pat. No. 5,616,577 to Nambi et al. discloses methods using hymenialdisine or debromohymenialdisine to inhibit protein kinase C.
U.S. Pat. No. 5,591,740 to Chipman et al. discloses using compositions comprising hymenialdisine or debromohymenialdisine to treat osteoarthritis.
U.S. Pat. No. 5,621,099 to Annoura et al. discloses a method for synthesizing hymenialdisine, bromohymenialdisine, and related compounds.
U.S. Pat. Nos. 5,834,609, 6,103,899, and 6,218,549, all to Horne et al. disclose bicyclic aminoimidizole compounds which have anti-tumor and antimicrobial activity.
U.S. Pat. Nos. 6,197,954 B1, 6,211,361, 6,528,646, and published U.S. Patent Application No. 2001/0012891A1, all to Horne et al., disclose processes for synthesizing hymenialdisine, related compounds, and their intermediates.
Published U.S. Patent Application No. 20030060457A1 to Schaffer et al. discloses that hymenialdisine is a cdk inhibitor which can be used as an inhibitor of gene expression, replication, and reactivation in pathogenic agents.
EP1106180A1 and WO0141768A2 to Meijer disclose using hymenialdisine and related compounds such as debromohymenialdisine to inhibit cyclin dependent kinases, GSK-3β, and casein kinase 1 for preventing and treating neurodegenerative disorders such as Alzheimer's disease, diabetes, inflammatory pathologies, and cancers.
DNA replication is a process that requires great accuracy and relies on surveillance mechanisms, which monitor DNA damage and initiate DNA repair (Zhou, B.-B. S., et al., Nature 408 433-439 (2000)). The inability to carry out DNA repair often leads to the transformation of normal cells into malignancies (Martin, N. M. B., J. Photochem. Photobiol. B 63 162-170 (2001)). Upon DNA damage, cell cycle checkpoints get activated, which delay cell cycle progression and allow DNA repair. A multi-faceted involvement of these checkpoint pathways regulates DNA repair, (Zhou, B.-B. S., et al., Nature 408 433-439 (2000; Martin, N. M. B., J. Photochem. Photobiol. B 63 162-170 (2001); and Zhao, S., et al., Nature 405, 473 (2000)) telomere length (Naito, T., et al., Nat. Genet. 20 203-206 (1998); Ritchie, K. B., et al., Mol. Cell Biol. 10 6065-6075 (1999)) and the induction of apoptotic cell death (Zhou, B.-B. S., et al., Nature 408 433-439 (2000); and Lowe, S. W., et al., Nature 362 847-849 (1993)). Protein kinases regulate a host of cellular processes such as growth and differentiation, cell proliferation and apoptosis (Sielecki, T. M., et al., J. Med. Chem. 43 1-18 (2000); Sridhar, R., et al., Pharm. Res. 17 1345-1353 (2000); Traxler, P., et al., J. Med. Res. Rev. 21 499-512 (2001); Scapin, G., Drug Discovery Today 7. (2001); Toogood, P. L., Med. Res. Rev. 21 487-498 ((2001); and Bridges, A. J., Chem. Rev. 101 2541-2572 (2001)). DNA damage caused by radiation or chemotherapy triggers the DNA damage-responsive protein kinases ATM and ATR, which activate Chk1 and Chk2. Chk1 and Chk2 in turn phosphorylate Cdc25 and prevent Cdc2 activation, resulting in cell cycle arrest (Curman, D., et al., J. Biol. Chem. 276 17914-17919 (2001)). Hence, small molecules that can inhibit the checkpoints may enhance the efficacy of DNA damaging chemotherapeutics or radiation therapy (Rundle, N. T., et al., J. Biol. Chem. 276 48231-48236 (2001); Jackson, J. R., et al., Cancer Res. 60 566-572 (2000); Koniaras, K., et al., Oncogene 20 7453-7463 (2001); Zhou, B.-B. S., et al., Cancer Biol. Ther. 2 S16-S22 (2003); Yu, Q., et al., Cancer Res. 62 5743-5748 (2002)).
In light of the prior art, there remains a need for other small molecules that have activities which exhibit a similar or better pharmacological profile to hymenialdisine and which are simple and inexpensive to prepare.